<!DOCTYPE html>
<html>

<head>
    <title>Bootstrap 实例</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="https://cdn.staticfile.org/twitter-bootstrap/4.3.1/css/bootstrap.min.css">
    <script src="https://cdn.staticfile.org/jquery/3.2.1/jquery.min.js"></script>
    <script src="https://cdn.staticfile.org/popper.js/1.15.0/umd/popper.min.js"></script>
    <script src="https://cdn.staticfile.org/twitter-bootstrap/4.3.1/js/bootstrap.min.js"></script>
    <style>
        /* Make the image fully responsive */
        .carousel-inner img {
            width: 100%;
            height: 100%;
        }
    </style>
</head>

<body>

    <div id="demo" class="carousel slide">

        <!-- 指示符 -->
        <ul class="carousel-indicators">
            <li data-target="#demo" data-slide-to="0" class="active"></li>
            <li data-target="#demo" data-slide-to="1"></li>
            <li data-target="#demo" data-slide-to="2"></li>
            <li data-target="#demo" data-slide-to="3"></li>
        </ul>

        <!-- 轮播图片 -->
        <div class="carousel-inner">
            <div class="carousel-item active">
                <img src="images/1.jpg">
            </div>
            <div class="carousel-item">
                <img src="images/2.jpg">
            </div>
            <div class="carousel-item">
                <img src="images/3.jpg">
            </div>
        </div>

        <!-- 左右切换按钮 -->
        <a class="carousel-control-prev" href="#demo" data-slide="prev">
            <span class="carousel-control-prev-icon"></span>
        </a>
        <a class="carousel-control-next" href="#demo" data-slide="next">
            <span class="carousel-control-next-icon"></span>
        </a>

    </div>

    <h1>这是一个轮播系统<h1>

</body>

</html>